Part of selling is being part of the community. People buy from people they know, people they see around, who contribute and make ck what it is. Maybe spend some time on the forums and get familiar with the community. Reputations are built up by your history, contributions, reliability, etc. Many people expect a level of safety and security when they are buying and that takes time. Maybe sell the stamp for pure and sell smaller things to get started. Or have pure and sell that plus custom orders. Something like that could work. Or just be patient, anybody spending $100+ probably looks towards familiarity first.